Process for manufacturing colloidal compounds



* Patented Sept. 17,1929

UNITED STATES aueusr cnwau, or vrmnu, aus'ram PROCESS FOR. WACTUBDTG GOLLODAL OOKPOURDB Io braving. Application iled octeber l, 1087, Serial Io. 224,284, and in Austria larch 80, 1927.

The invention relates to a process for the mechanical dispersion of water insoluble salts of the arsenic acids and of. the phosphoric acids, b the term water insoluble salts being un erstood the earth-alkali salts and the heavy metal salts of the respective acids.

As is well known, arsenic acids and phosphoric acids as well as their salts show a far going afiinity (close relationship) and in 10 many respects behave ve similarly or quite analogously. In view 0 this fact the term salts of acids of the arsenic grou T is employed in the following for the sa ts of the arsenic acids as well as for those of the phosphoric acids.

It is known that the insoluble salts of acids of the arsenic oup, such as for instance arsenates of lea copper, calcium or calcium phosphates can only with at difliculties be 90 transformed into the colloidal state.

According to the present invention dispersing of insoluble salts of the acids of the arsenic up iscarried out in the presence of alka i salts of water poor acids of the arsenic group, that is to say of alkali salts of those hosphoric and arsenic acids, which are ormed from the ortho-acids by water being split 05 or which may be regarded as having been formed in this manner I have found that the alkali salts of these water poor acids perform an excellent action as peptizators. Of these alkali salts of water m9; acids of the arsenic group may fo'r'iH- Baum named the alkali-metah hates (salts of meta-phosphoric acid H P0,), particularly lymeric alkali-meta-phos phates,

such as of s tgfihetaphos hates, tetramety pho hates, hwtadifiglates, e. g. potas sium-so mm-me exap osphate; the alkalipyrophosphates (salts, of pyrophosphoric acid H,P,O,), the -alkali-meta-arsenates (salts of meta-arsenic acid HAsO,) and a1 kali-pyro-arsenates, e. g. sodium-pyroarsenate (Na As,O,). Moreover, belong to this kind of peptizing agents also thealkali salts of the corresponding thio-acids, that-is to say the salts of the water poor acids of the arsenic group, in which the oxy on of the acids is entirely or partly replace by sulfur. Of this timately disinte kind of salts particularly sodium-pyro-thioarsenate has been found very effective.

It is of particular importance, that by means o'fthese ptizing agents calcium arsenate, which hit erto could only be worked up to coarse dispersions, can be broughtinto the truly colloidal state. The transformation into this state is advanced, if the calcium arsenate employed as raw material is prior to the mechanical treatment freed from water. so The best result is obtained, if the calcium arsenate is for this purpose dehydrated by heating it considerably above 100 C. up to 600 C. The colloidal calcium arsenate is characterized by the fact, that it has, when distributed vin water, a hydrogen ion concentration between P =7.07 and P =10. Owing to this concentration, which coincides with the neutral point or is very close to it, there is no risk of plants being burnt or deteriorated, when the said colloid is employed. for destroying the plant parasites.

For producing the disperse system any known mechanical means, such as heating mills, colloid mills and the like may be employed. But it is also sufficient to intimately mix the material to be dispersed with the peptizing agent, for instance by means of a simple agitator. Advantageously the mechanical treatment is carried out in the presence of protective colloids for instance an fite liquor. Ihe'material to be comminuted may bedisintegrated either in-a d or in a moisted or in a perfectly wet state, or instance under addition of water.

Examples 1. 1000 grammes of calcium arsenate are together with 800 grammes of water and 50 grammes of tassium-sodium-hexametaphosphate for instance in a. colloid-mill inted and beaten during 60 4 minutes. This rsion may also be carried out in grhesence of '50 grammes of sulfiteii nor. e product thus obtained is a paste,

w 'ch, when mixed with water, ives a colloidal solution. The paste may dried by means of a roller drying apparatus or by p y g it t g a azz i e W par- -' arsenate are with 100 grammes of d Also the dried product can be dissolved in water.

2. 1000 grammes of calcium arsenate are with 800 grammes of water triturated in a colloid-1nill during minutes while 100 grammes of sodium-pyro-thio-arsenate are added successively by rtions. The resulting pastemay be drie in the manner indicated in Example 1, the dry product dissolves 'ust as well as the pasty product in water.

he colloidal solution shows the Brown movement characteristic for true colloids.

3. 1000 grammes of calcium phosphate are with 800 grammes of water and 100 grammes of sodium-pyrophosphate beaten in a colloidmill during minutes. The resulting paste is just as is the case in Examples 1 and 2 homogeneous, it can be dried according to Example 1 and the product behaves in the dry state as well as in the moisted state towards water as a colloid.

4. 1000 grammes of lead arsenate are triturated with 800 grammes of water and 70 grammes of sodium-pyro-thio-arsenate in a colloid mill durin 30 minutes. The resulting paste is a col oid and gives with water just as the products of Examples 1 to 3 good colloidal solutions, showing all the characteristic features of such solutions. Also this product may be dried by means of a spraying apparatus and the dried product gives just as the paste stable colloidal solutions.

5. 1000 grammes of dehydrated calcium 1- um-pyrophosphate in a ball mill isintegrated during one hour in the dry state. The resulting product, which, if desired, may be pzssed through a sieve, gives with water autiful, excellent, stable colloidal solutions, which show all the characteristics of truly colloidal solutions, viz the Brown movement, the Tyndall phenomenon and the property of being precipitated in the form of flocks by neutral electrolytes.

In the following claims I use the term insoluble salts of the arsu ic group to include the earth alkali salts and the heavy metal salts of the arsenic acids and of the phosphoric acids. The term water poor acids of the arsenic group is intended to include the arsenic acids and phosphoric acids, which are formed from the ortho-acids by water being split off or which may be regardedas having been formed in this manner, oxy-acids being included as well as those corresponding acids, in which the oxygen is entirely or partly replaced by sulfur.

What I claim is: 1. In the art of producing colloidal compounds the step which consists in mechanicaly dispersing insoluble salts of acids of the arsenic group in the presence of alkali salts of water poor acids of the arsenic group.

2. In the art of producing colloidal coma, (woman ounds the step which consists in mechanicaly dispersing insoluble salts of acids of the arsenic group in the presence of alkali salts of water poor acids of the arsenic group and of protective colloids.

3. In the art of producing colloidal compounds the step which consists in mechanically dispersing insoluble salts of acids of the arsenic group in the presence of an alkali pyrophosphate.

4. n the art of producing colloidal compounds the step which consists in mechanically dispersing insoluble salts of acids of the arsenic group in the presence of sodium-pyrophosphate.

5. In the art of producing colloidal compounds the step which consists in mechanically dispersing calcium arsenate in the presence of alkali salts of water poor acids of the arsenic group.

6. In the art of producing colloidal compounds the step which consists in mechanically dispersing calcium arsenate in the presence of alkali salts of the water poor acids of the arsenic group and of protective colloids.

7. In the art of producing colloidal compounds the step w ich consists in mechanically dispersing previously heated calcium arsenate 1n the presence of alkali salts of water poor acids of the arsenic group.

8. In the art of producing colloidal compounds the step w ich consists in mechanically dispersing calcium arsenate which previously had been heated above C. up to 600 C., in the presence of alkali salts of water poor acids of the arsenic group.

9. In the art of roducing colloidal comounds the step which consists in mechanically dispersing calcium arsenate in the presence of an alkali pyro-phosphate.

10. In the art of producing colloidal comounds the step which consists in mechanically dispersing calciuin arsenate in the presence of sodium-pyrophosphate.

11. In the art of poducing colloidal comunds the steps which consist in dry-grindmg insoluble salts of acids of the arsenic group in the presence of alkali salts of water r acids of the arsenic group.

12. In the art of producing colloidal compounds the steps which comprise grinding calcium-arsenate in presence of alkali salts of water pooracids of the arsenic group, both of which are in 'a dry state.

13. In the art of producing colloidal compounds the steps which comprise grinding calcium-arsenate in resence of an alkali pyrophosphate, both 0 which are in a dr state.

14. In the art of producing colloi al calcium arsenate the step which consists in drygrinding partly dehydrated calcium arsenate 1n. the presence of water poor acids of the arsenicgroup.

15. In the art of producing colloidal calcium arsenate the step which consists in dr inding calcium arsenate which previous y ad been heated above 100 C. up to 600 C., in the presence of water poor acids of the arsenic group.

16. A dry mixture for a ricultural use,

consisting of a salt of an aci of the arsenic group and of an alkali salt of a water poor acid of the arsenic group.

17. A dry fnixture for use in destroying the animal parasites of plants, consisting of a salt of arsenic acid and of a water poor acid of the arsenic group.

18. A dry mixture for use in destroyin the animal parasites of plants, consisting o calcilpm .arsenate and .of an alkali-pyrophosate.

P 19. A dry mixture for use in destroyin the animal parasites of plants, consisting o calcium arsenate, sodium pyrophosphate and of a protective colloid.

20. A dry mixture for use in destroying animal parasites of lants, consistin of calcium arsenate and 0 an alkali salt 0 a water poor acid of the arsenic group, which mixture, when distributed in water, has a hydroen ion concentration between P ;7.07 and In testimony whereof I have afiixed my signature.

AUGUST CHWALA. 

